3.
1 had fallen hurt
2 had taken
3 had washed
4 had left
5 had done
6 came
7 examined
4.
1 The day before yesterday nurse had made all the injections by 2 o'clock
2 My toothache dissapeared after I had taken a tablet
3 They had built (тут по-хорошему должен быть артикль "a”) new hospital in the village by September 2010
4 Before the headmaster entered the classroom, students had written the Latin dictation (я написал так, но тут возможны вариации в зависимости от того, что хотим сказать: директор вошёл в класс до того как ученики написали диктант или ученики написали диктант до того как директор вошёл в класс. Лично я выбрал второй)
В четвёртом не стал писать предложения целиком, а просто исправил ошибки с глаголами
Minsk is situated on the river Svisloch and occupies an area of 200 square kilometers. Its population is about 2 million people. During the Great Patriotic War Minsk was destroyed by German invaders almost completely. Minsk lay in ruins. The people of Belarus rebuilt the city. Victory Square, the Eternal Flame at the monument commemorates soldiers, underground fighters, partisans who fell in the battles for freedom f our motherland. The names of many streets of the city commemorate many heroes.